With the development of mobile communications, there are more application scenarios where multiple frequencies coexist in a base station subsystem. As frequency bands are increasing, the quantity of radio frequency modules and the quantity of antennas at a site are also gradually increased. As a result, the site becomes more crowded, and site deployment and installation become more difficult. Currently, equipment vendors and operators mainly use a scheme that combines a broadband antenna, an external combiner, and an external active module, where the combiner is connected to the external active module by a conducting wire to implement the sharing of an antenna system by multiple frequency bands. In this scheme, unit parts that form a whole antenna are dispersed, and site installation requires large space, making it difficult to perform site installation.